FLOW DYNAMICS AND BENDING OF WIDE-ANGLE TAILED RADIO-SOURCES

VLA observations of 11 wide-angle tailed radio sources (WATs) at 6 and 20 cm are used to study the dynamics of this class of source. These n ew images, in conjunction with optical and X-ray data, are used to des cribe the unifying characteristics of this class. WATs are found in th e centers of clusters without cooling cores, associated with galaxies of low space velocity. They are large sources, extending at least 50 k pc from the cluster center, and they have radio power close to the Fan aroff-Riley (F-R) I/II break. They show a distinctive jet-hot spot tra nsition which is not seen in either F-R type II sources, or in lower p ower F-R type I sources. The bend into the characteristic C shape occu rs at the hot spots. We use the surface brightness and spectral distri butions to model the flow fields and bending dynamics of the sources. We use two limiting models, the adiabatic model (in which no in situ e nergization takes place), and the kinetic model (in which all of the r adio luminosity comes from in situ energization). We find the sources cannot be bent by the slow galaxy motion in the kinetic model. We find the sources can be bent by the ram pressure of a slowly moving centra l galaxy in the adiabatic model. However, this model has serious probl ems reconciling the particle lifetime and the travel time down the tai l.